Answer:
2H⁺(aq) + 2e⁻ → H₂(g)
Explanation:
In a redox reaction, one substance is oxidized (Loosing electrons) and the other substance is reduced (Gaining electrons).
In the reaction:
Zn(s) + 2H⁺(aq) → Zn²⁺(aq) + H₂(g)
The Zn is loosing 2 electrons (From oxidation state = 0 to oxidation state = +2). That means is beeing oxidized.
And the hydrogen is gaining one electron each atom (From oxidation state +1 to oxidation state 0). Hydrogen is beeing reduced.The half-reaction that represents its reduction is:
2H⁺(aq) + 2e⁻ → H₂(g)
